The area under the curve y=1/x from x=8 to x=10 is revolved about the x-axis. What is the volume of the solid formed?

1 Answer
Apr 1, 2017

pi/40

Explanation:

The region bound by these curves can be thought of as the region bound by y=1/x and the x axis, between x=8 and x=10.

Hence, V=piint_8^10(1/x)^2dx

=piint_8^10(1/(x^2))dx

=piint_8^10x^-2dx

=pi[x^-1/-1]_8^10

=-pi[1/x]_8^10

=-pi(1/10-1/8)

=-pi(-1/40)
=pi/40